The Environmental Health Sciences (EHS) Center at Oregon State University is an interdisciplinary unit of 35 Center investigators and now in its 39th year of existence. The mission of the EHS Center is to foster excellent research and technology development into the fundamental causes and progression of environmentally related diseases;to advance our ability to predict, prevent, and mitigate environmental insults and promote health;and to disseminate this knowledge to educate the government and public to make informed decisions. The theme for the Oregon State University (OSU) EHS Center is to advance our knowledge concerning the actions of environmental agents at the molecular and cellular level and to understand how we can modulate our individual susceptibility to improve health. To achieve these objectives, the Center continues to develop pioneering analytical capabilities, investigate model systems, and apply the results to realworld problems. The results of this research enabled by the Center contribute to the scientific basis for the prediction of health risks due to exposure to environmental chemicals, aid in the development of innovative approaches for use in risk assessment, and to minimize the impact of environmental stresses on human health. The broad intellectual base of expertise, research, and teaching allows the Center to conduct innovative environmental health-related studies across campus through collaborations and sharing of expertise. Three Research Cores focus collaborative research into the broad themes of: (1) Environmental Mutagenesis and Carcinogenesis, (2) Biomolecular and Environmental Chemistry, and (3) Signaling and Oxidative Stress. Four Facility Cores provide scientists with access to expertise, services, and major equipment in specific research technologies. (1) Aquatic Models, (2) Mass Spectrometry, (3) Cell Imaging and Analysis, and (4) Integrated Human Health Core-newly formed from the Statistics Core and a clinical study coordinator. The EHS Center grant also supports the Administration Core and an expanded Pilot Project Program. Because of Center guideline changes, this Center will be merged with the OSU Marine and Freshwater Biomedical Sciences Center, enabling the largest vertebrate animal studies (with 40,000 trout) on carcinogenesis and cancer prevention in the Aquatic Models Facility Core. New capabilities to conduct large-scale toxicology studies using zebrafish are being developed. BACKGROUND This Center, which is one of the original six NIEHS Centers, is applying for years 39-43. This is a revised application of a competing continuation application. The Center has undergone substantial reorganization because of retirements, and new hires, and, of course, the new Center guidelines. The overall theme remains advancing knowledge concerning the actions of environmental agents at the molecular and cellular level and understanding how we can modulate individual susceptibility to improve health. The Center has three long-range goals: 1) to understand the mechanisms for reducing individual susceptibility;2) to assess health risks at low exposures (with emphasis on large numbers through their aquatic capabilities;and 3) macromolecular interactions. During the last period of support, the Center members obtained one Program Project grant, a Training grant and a Short-Term Minority Undergraduate Training grant, as well as individual grants. Additionally, two new Center-affiliated Program Project grants and 1 Training grant were awarded. There has been a restructuring from the previous structure of seven Facility Cores to the current four: 1) Aquatic Models;2) Mass Spectrometry;3) Cell Imaging and Analysis;and 4) Integrated Human Health Core. The fourth Core is a merger of the original Statistics Core and a clinical study coordinator. A formal Community Outreach and Education Core is not proposed in this application. The Center also has an Administrative Core and a Pilot Project Program. ESSENTIAL CHARACTERISTICS Strategic Vision and Impact on Environmental Health